So what are the goals of information visualization? IV-tools aim at allowing the user to interactively explore data at various levels of abstraction, for example the user can start with an overview of the whole dataset visualized in just one screen, and then notice an interesting pattern and zooming in that pattern, change the level of abstraction, go into much more detail on the subset of data of interest. Another important goal is to give users a greater sense of engagement with data, the ability of flying through or walking into the data, manipulating the dataset, changing something on one part of the dataset and seeing what other parts change as an effect of that change. This all allows to understand better the dataset and if our visualization is intuitive and it is easy to grasp we can also encourage the discovery of some details or some cause-effect relations among different variables which could be very difficult to understand otherwise.